There are various techniques and numerous prefabricated models available for post-operative application. However, none have a dynamic composite strut assembly and all are subject to material inconsistency and material fatigue.
The Oregon Orthotic system is a custom fabricated device that incorporates a rigid lamination technique that may include mechanical articulations for motion control. A further alternative is a Dynamic response AFO which incorporates a silicone matrix to provide increase flexibility in a custom fabricated device.
Hinged orthotic designs have been constructed in the past from either thermoplastics, laminates or metal with various hinge designs, in various configurations, and with different combinations of materials. These provided the orthotist an ability to alter motion control of the involved extremity using combinations of springs, elastic/urethane flexures or rigid mechanical stops, either fixed or adjustable. The mechanical hinged designs are subject to wear and noise. They also include a rigid stopping point that can impede a smooth, consistent motion through the stance phase of gait. The position of the mechanical stop is usually optimized for a stride length but cannot be varied with velocity or stride length. Hinged designs also tend to be bulky and heavy with the hinges placed on either medial, lateral or both sides of the ankle.